As president of Iran, Mahmoud Ahmadinejad has been nothing if not controversial. Internationally, he has goaded the Israelis and their American allies with his views about the Jewish holocaust, while his government’s populist economic policies have stirred domestic controversy unknown since the 1979 Islamic Revolution.

But with a presidential election due next June, Ahmadinejad is well into his last year in office, given the two-term constitutional limit. The change will be welcomed by most of Iran’s establishment, including senior clerics and close associates of Ayatollah Ali Khamenei, the rahbar (leader).

The election comes at a crucial time, with tightening Western sanctions that have halved Iran’s oil exports to around 1.1 million barrels a day and have helped spark depreciation of the nation’s currency, the rial, that accelerated dramatically last month.

Khamenei will be keen to see the poll pass off peacefully and won by a less volatile figure than Ahmadinejad. But recent Iranian presidential elections have been unpredictable — Ahmadinejad’s victory in 2005 was a surprise, and his re-election in 2009 produced the largest street protests since the Revolution.

Iranian presidential elections are partly managed, firstly because the Guardian Council, a constitutional watchdog body, vets candidates. But Iran has weak political parties, and the voting system is almost haphazard; if no one wins 50 percent, the two best-placed candidates enter a run-off, and with many contenders — there were seven in 2005 — 20 percent or so of votes can take a candidate through.

For Khamenei, one priority will be to avoid a repeat of 2009, when reformist candidates alleged the poll was rigged and the suppression of street protests sent Iran into a period of tightened political control.

The Guardian Council may well bar reformist candidates, as it did in 2005 before Khamenei intervened to reinstate Mustafa Moein and Mohsen Mehrali-Zadeh. But it may concern the leader that blocking reformists, who might then call a boycott, would hardly restore the legitimacy the system lost in 2009.

It is widely expected, however, that the Guardian Council will bar Esfandiar Rahim Mashaei, or any other associate of Ahmadinejad. Mashaei has been at the center of Ahmadinejad’s tension with Khamenei — indeed the leader overruled the president in 2009 when he appointed Mashaei as first vice-president, instead appointing him chief of staff. Later spats over Ahmadinejad’s removal of the intelligence minister originated in the maneuvering of Mashaei, whom one senior cleric accused of sorcery. In any case, Ahmadinejad and Mashaei have failed to create a sustainable political current that could propel an Ahmadinejad ally into the president’s office. Their efforts to sponsor lists for local and parliamentary elections have fared poorly.

That suits Khamenei, whose priorities are a quiet election and a president with a safe pair of hands. The leader would like a new president to calm Iranian politics by mending relations with parliament, the leader’s office, senior clerics and the central bank. This might also improve economic management in the face of sanctions. It could also tighten co-ordination over the nuclear program between the presidency, the Supreme National Security Council and the leader’s office. Iran is open to compromise but has red lines over its ‘right’ to enrich uranium, and any agreement will require skillful negotiating, as well as carrying domestic opinion. Given the election’s importance, the media is already weighing up potential candidates. Ali Larijani, parliamentary speaker and establishment insider, is liked by Khamenei, but lacks charisma and won only 5.9 percent of the 2005 vote.

Mohsen Rezaie, Islamic Revolutionary Guards Corps (IRGC) commander from 1981 to 1997, has also been suggested. But he appeared in 2005 even less appealing than Larijani, and withdrew shortly before polling.

Other names bandied about are Gholam-Ali Haddad-Adel, former parliamentary speaker; Manuchehr Mottaki, former foreign minister, and Saeed Jalili, the security official who has led Iranian negotiators in talks over the nuclear program.

A more effective candidate could be the charismatic Mohammad-Bagher Ghalibaf, Tehran’s mayor since 2005 and a former senior IRGC officer, though he received only 13.9 percent of the vote in 2005. In an interview in September with the Italian newspaper Corriere della Sera, Ghalibaf spoke of “moderation” in foreign policy while keeping “firm lines” on “fundamental questions”; as well as diverting oil revenue from current spending into productive investment.

This is exactly what Khamenei needs. This far out from June 2013, Ghalibaf looks like the man to beat.

Gareth Smyth has reported from around the Middle East for almost two decades and is the former Financial Times correspondent for Tehran